EUROPAN CREATURE (EUROPA REPORT 2013)
An unknown kind of bioluminescent tentacled creature was discovered by the first manned mission to Europa. It lives in the oceans beneath the ice in the region known as the Conamara Chaos, where the ice layer is thin enough to allow sunlight to pass through and microscopic algae to grow, and the seafloor is filled with hydrothermal vents that provide nutrients and energy for a strange yet thriving ecosystem.
This creature appears to be a rather intelligent predator; strong enough and cunning enough to break through the ice when detecting surface beings in order to drag them underwater, presumably to devour them. This behavior might imply that there are naturally occurring life forms on the surface of Europa, on which it preys. However, it is equally possible that the creature had never encountered surface dwellers before and was displaying intelligent behavior.